As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE COMPLETING T/C N8420001, FOUND UPPER FAN FIRE DETECTOR TEFLON BUSHING WORN IN MULTIPLE PLACES FOR THE NR 2 ENGINE. ACFT GROUNDED. REMOVED AND REPLACED THE NR 2 ENGINE UPPER FAN FIRE DETECTOR IAW AMM 26-11-01/401. OPERATIONAL CHECK SATISFACTORY.